Radio tuning mechanism



May 13, 1941.

S. S. CRAMER RADIO TUNING MECHANI 5M Filed May 9, 1940 BY ,8 I A1I'TORNEY Patented May 13, 1941 RADIO TUNING MECHANISM Stanley S. Cramer, Haddon Heights, N. J., assign- I or to Radio Condenser Company, Camden,

Application May 9, 1940, Serial N0. 334,151

{23 Claim.

This invention relates to a special combination and unitary structure for use in connection with radio receiving sets.

Numerous radio receiving sets are being made today in which push-button tuners are used, wherein the push-button structure for operating the tuning condenser is made as a separate unit from the condenser or tuning elements per se, some form of indirect drive being used to couple the push-button unit with the condenser tuning unit.

Instead of having two independent units with the interconnecting coupling means, my present invention is directed to a single unitary structure in which the tuning condenser or condensers and the push-button parts are incorporated with or carried by the same frame members. By combining the various parts into a unitary structure, I reduce the size and cost of the radio tuning equipment, thereby fulfilling one of the principal objects of my invention.

Another object of my invention is to provide a construction in which the tuning elements, such as the stator and rotor of a variable condenser, are so arranged that the full range or capacity of I the condenser may be covered by a direct-acting push-button unit, without any intermediate gearing.

An important object of my invention is to provide new and novel means for taking out back-lash and wobble in the tuning units.

A further object of my invention is to provide new and novel means for adjusting and locking the setting device which controls the movement of the rotorshaft without throwing the tuning element off the set resonance point.

Other and more specific objects will be apparent to one skilled in the construction of such equipment to which this invention relates.

In the drawing:

Figure 1 is a plan view of a two-gang condenser incorporated in the unitary structure,

Figure I is a fragmentary, perspective view of the parts shown on theline 1-1 of Figure 6.

In the various views, wherein like numbers refer to corresponding parts, I is a front frame member having lugs 2 and 3 bent backwardly, which are attached in any suitable manner as by screws 4 to the end plates 5 and 6 which are fastened together by studs I and 8 in a manner such as disclosed in my Patent No. 2,101,985, isused December 14, 1937.

As an alternative, the frame member I may be omitted and the end plates 5 and 6 bent out-.

wardly to form what are now the extending ends 9 and III of the frame member I. By constructing the end plates 5 and 6 in this last-mentioned manner, the front portions of the stators II and I2 are left exposed. I prefer to mount the stators II and I2 to the frame bars or rods I and 8 in the manner disclosed in my Patent No.

2,187,017, issued January 16, 1940. Further descrlptlon of the frame and mounting of the stator therein is therefore not necessary.

The rotor plates of the condensers are mounted directly on the rotor shaft l3 which, in turn, is supported in the end plates 5 and 6 in the manner disclosed in my Patent No. 1,800,719, issued April 14, 1931. The rotor shaft I3 extends through the end plates 5 and 6 to receive setting devices, two forms of which and two,

methods of mounting are shown in Figure-1.

In the preferred form, shown in the two pushbutton structures at the left of Figure 1, the'setting device I4 comprises a punching of suitable sheet metal such as steel, comprising a fiat portion wtih two arcuately formed edges I5 and I8 and a. circular or ring portion I! held to the plate portion I4 byan integral yoke I8. The plate portion I4 and ring I] have holes I9 and 20 respectively therein which are adapted to make a snug fit with the rotor shaft I3. Positioned between the plate I4 and ring I! is a bushing 2| having a screw-threaded hole 22 to receive a set screw 23 which is adapted to pass through a hole 24 in the yoke I8 and into the bushing 2| and against the shaft I3, thereby drawing the bushing against the shaft to form a double lock between "to -set a for. the

The projection 32 in its enis or the flat plate por-.

within its mounting lugs 40 and 4 i Sumcient pressure is put against the button 38, either by the fingers engaging the knurled portion of the button or by a screw-driver in the slot 45, to cause this engagement of the screw -driverfend 44 with the screw slot against the compression inner edge thereof. This will force the inner 7 end of the slidable member 33 downwardly so that the upper edge 64 of the slot 34 is drawn downwardly against the shaft 33. Y

One end of the sliding member 33 has a two step end reduction, one step, flpbeing adapted to project through and fit in slots in the frame portion 3. The other step portion, 33 V wider than the portion 35 so as toprovide ders for stopping the plate 33 against the frame member 3,

due to the action of the retracting spring 31 after the finger has been released from a button 33 carried by a rod 39 which, in turn, is supported by front and rear. lugs 43 and 4i, respectively, punched outwardly from the slidable plate member 33. It will be noted that the return spring 31 in Figure 2 acts at an angle to assist in holdend of a spring 43 is seated, the other end of the spring being seated against the lug I4]. The}.

spring 43 is stiff enough so that for normalioperatlon or tuning in of the stations, by any one of the push-buttons, it is compressed Just a little, 3

or not at all by the pressure required toturn the rotor of the condenser.

The collar 43' be made integral with the rod 33, orthe rod 33v may-have an annular groove therein to receive a'snap ring which would then form'thecollar 42; v The inner end of the rod is fiattenedat 144.

to form an end similar to a screw driverto en- Sage-the slot in the screw 23 for apurp ose. so

which'will be later pointed out. v. v

Thej outer' end of the push-rod 33 ispreferably alsofiattened to flt'a-slot cast in'the button '38 which in turn may have -a screw-driver slot fo r a purpose which will be hereinafter pointed out;

In the form of setting member shown to the right of Figure 1, the setting'member is spaced fromthe end plate 6 by a collar 43, and the,

yoke portion i8 itself is threaded, and the screw 23 pushes directly against the spring member 26, 'which ;may be bowed to fit the periphery of theshaft-fl-sas shown in Figure 3. In this 11 Inr'e, 'th'e'settin'g member has two-fiat'engaging of the spring 43 The set screw is loosened and the station is tuned in by a manual control means which is not shown, and the screw 23;

is tightened up to lock the setting member i4 inrits tuned position, it being understood that the slidable member 33 is in a position so that the projections or fingers 3i (and 32 engage their respective seats 33 and 30 on the setting member i4. After this station has been set to its tuned position, all that required to bring in this statlonthe next time, is merely to push in its corresponding button 33. i

To overcome any up-and-down lost motion i the outer end 35 of the sliding member 33, a bar 41 isfastened to the frame portions 3 and ill by means of screws 43, there being a separate plate 41 for each pair of push-buttons.

An alternative construction is shown in Figures 5 and 6, in which a thin, resilient plate member 48, preferably of spring steel, is used instead of the bars 41. In this construction the plate 43, which need only be fastened-at one end '43 and move this gme n ber', ,whji Je -preferably sli htly bowed at the Ecenter, rl'the frame member 3;-' -.The=fit of'fth'e bali ixinithe sprlns member 43 willltheh 'eliminilte fillwobble;in this end of, the push-button plate 3.8.] Further'more. since the member 43' is: slotted lt Ca ln irm somewhatsideways to accommodate the partial entry. of the bail 5|, without'sever -binding, but

sufliciently to prevent.jup-a'nd-down or side- 1 wobble, thus inuring' to the more accurate setof the setting device. while I have shown the push-button tuners on both sides of the tuning condenser, they may of course beplaiced'together on one side. Fursurfaces fl. s'imilar tothe one known inFlgurej.

By utilizing {the form of construction shown at the left ofv Fi e 1, as heretofore described, instead of the arrangement shown to the right of Figure 1, it will be noted that the entire 2 structure may be shortened materially. In the operatioir 'ot the'structure, and referring to Figures d V erstb mhat r i'gageithe' slot in the-screw fl, it being, he gipu'sh-rod 39 is rotatable 75 for carrying said actuating means, and 'a setand 2, when it is desired station ozra. given frequency, the butthermore. the construction i the tuningimech' anism per se may be moufi ed in a-frame separate from the condenser frame as ad-ihdependent tuner, which may be connectedftdthe rotor shaft of the condenser in any satisfactory manner.

From what/has been said, it will be appre iated that ,niany of the details for carryin improved construction into operative-y; feil'e may be varied without departing from the-spirit;

the scope of the appended,

,totuning position, each slidable member having a slot through which the rotor shaft passes, and projections located one on opposite sides of said slot but on the same side of the slidable member which also haslugs on'this same side ting device adjustably carried on and fastened to the rotor shaft and having surfaces and stop parts disposed on opposite sides of the rotor shaft and engaged by said projections to turn the setting device and rotor shaft in a direction according to the predetermined adjustment of the setting device.

2. A structure as set forth in claim 1, further defined in that the setting device includes a fiat portion carrying said proJection-engaging-surfaces, and a ring portion connected by a yoke. the rotor shaft passing through both the flat portion and the ring, a screw going through the yoke and acting to fasten the setting device in position on the rotor shaft.

3. A'structure as set forth in claim 1, further defined in that the setting device includes a; flat portion carrying said proiection-engaging-surfaces, and a ring portion connected by a yoke. the rotor shaft passing through both the flat portion and the ring; the yoke having oppositely disposed fingers, a resilient metallic member located between the-yoke and rotor shaft and having slots for receiving said yoke finger, and a screw going through the yoke and acting to fasten the setting device in position on the rotor shaft.

4. A structure as set forth in claim 1, further defined in that the setting device includes a fiat portion carrying said proJection-engaging-surfaces, and a ring portion connected by a yoke, the rotor shaft passing throughhoth the flat portion and the ring, the yoke having oppositely disposed fingers, a resilient metallic member located be tween the yoke and rotor shaft and having slots forreceiving said yoke finger, the resilient member having its central portion curved to arcuately engage the rotor shaft over a considerable area, and a screw going through the yoke and forcing the curved part of the resilient member into clamping engagement with the rotor shaft.

5. A structure as set forth in claim 1, further defined in that the setting device includes a fiat portion carrying said projection-engaging surfaces, and a ring portion connected by a yoke, a bushing positioned between the ring and fiat portions, the rotor shaft passing through both the fiat and ring portions as well as the bushing, and a screw going through the yoke and into the bushing to clamp the setting device securely to the rotor shaft.

6. Astructure as set forth in claim 1, further defined in that the setting device includes a fiat portion carrying said projection-engaging surfaces, and a ring portion connected by a yoke,

and a screw going through the yoke into thebushing to draw the two toward each other and securely clamp the setting device to the rotor shaft.

which said fingers pass, and a screw going through the yoke and resilient member 'intothe bushing for clamping the setting device to the rotor shaft.

8. A structure as set forth in claim 1, further defined in that the surfaces on the setting device which are engaged by said projections are arcuately formed parts on the edge of a fiat portion of the setting device, while the stop parts are straight edges which form right. angles to the axis of the slidable member when the parts are in tuning position. 1

9. A structure as set forthin claim 1, further defined in that the surfaces on the setting device which are engaged by said projections are arcuately formed parts on the edge of a flat portion of the setting device, while at least one stop part is a straight edge which forms substantially a right angle with the axis of the slidable memher when the parts are in tuning position, the other stop part being a notch into which its cooperating projection on the slidable member extends in the manner described at the tuning position.

10. A structure as set forth in claim 1, further defined in that the actuating means comprises a push-rod slidably' carried by said lugs, the rod having a fixed collar positioned against the outer lug'when the slidable member is in normal idle position, and a spring between the collar and the inner lug'of suflicient strengthto allow the slidable member to be moved to tuning position with little or no further compression of the spring beyond its normal tension. I

11. A structure as set forth in claim 1, further defined in that the actuating means includes a push-rod rotatably and slidably carried by said lugs, the rod having a fixed collar spaced from the rear lug and a relatively stiff spiral spring 7. A structure-as set forth in claim 1, further'65 defined in that the setting device includes a fiat portion carrying said projection-engaging surfaces, and a ring portion connected by a yoke, a bushing positioned between the ring and flat portions, the rotor shaft passing through both the fiat and ring portions as well as the bushing, the yoke having oppositely disposed fingers extending over opposite portions of the bushing,

a resilient metallic member located between the yoke and the bushing and having slots through positioned between the collar and the rear ing, the spring being still enough to permitfull movement of the slidable member to tuning position without being compressed any substantial amount, the inner end of the push-rod terminating in a screw-driver point that is in alignment with the fastening means on the setting device which in turn is adapted to be engaged by the screw-driver point of the rod or; extra pressure being applied thereto, whereby the fastening may be operated to adjust the. setting device.

12.'A unitarystructure for the purpose described including a frame and at least one stator and rotor having a shaft carried by the frame slidable member, longitudinally spaced lugs on eachslidable member and a push-rod carriedby said lugs, and a setting device for eachslidablemember adjustably carried on the rotor s'haftand having a part with surfaces adapted to be en'- gaged by said projections to turn the setting device androtor shaft to a fixed position as determined by the adjustment of the setting device.

.13. Aunitary structure for the purpose described including a frame and at least one stator and rotor having a shaft carried by the frame and extending through the frame on opposite to said shaft extensions,- .each slidable member having a slot therein through which the related rotor shaft end passes, projections on each slidable member, located one on each side of the slot but in vertical alignment on the same side of the slidable member, longitudinally spaced lugs on each slidable member and a push-rod carried by said lugs, the rod being rotatable in said lugs and having a collar spaced from the rear lug and and a plate portion extending across the shaft and joined by a yoke to the ring, the rotor shaft going through boththe plate and ring, the plate portion having cam edges at opposite ends, the

cam edges terminating in stop-portions, the engaging means on the slidable plate being projections offset therefrom, while the fastening means on the setting device includes a bushing on the rotor shaft located between said ring and yokeconnected plate, and a resilient metal strip between the yoke and bushing, with means for holding the said strip in position and a screw "going through the yoke, the strip and into the characterized in that the, slidable members are flat metal'stripsset on edge in the frame, and metal bars are fastened to a frame member across and in engagement with the edges of the slidable member in pairs for the purpose described.

15. A. structure as set forth in claim 1, further characterized in that the slidable members are flat metal strips set on edge in the frame, balllike pieces set in the outer ends of said slidable members and thin flat spring strips fastened to the outer surfaces of a front frame member, the strips having holes therein slightly smaller than said ball pieces, the strips being slitted for a distance from said holes to receive the slidable member and to also allow cooperative action between the spring and ball piece for the purpose described.

16. In a tuning structure for a radio-receiving ate it so the setting device may be adjusted to a 4 desired setting, means on the slidable plate for engaging the setting device to turn it and the rotor shaft in the desired direction, and means on the push-rod for allowing it to be moved Ion gitudinally beyond its position for normal tunjections offset therefrom, while th fastening means on the setting device includes a bushing on the rotor shaft located between said ring and yoke connected plate with a screw going through the yoke and into the bushing.

18. A tuning structure as set forth in claim 16, further defined in that the setting device comprises a metallic member having a ring portion bushing to the shaft, and means on an outer member of the frame for preventing wobble in the outer end of the slidable plate.

19. Tuning means for a radio-receiving set including a frame, a shaft carried by the frame andoperatively connected with a tuning element, a setting device carried on the shaft and having fastening means for securing it to the shaft, a slidable member having one end supported by the shaft and the other end by a frame member, a push-rod rotatably mounted on one side of the slidable member and also being mounted for longitudinal movement, independent of movement of the slidable member, the end of the'rod being formed to engage said fastening means on the setting device when it is given said independent movement, so as to act on the fastening means for releasing and fastening. the setting device in an adjusted position on said shaft, and means on the slidable member for moving the setting device to turn the shaft in either direction of rotation accord- 'ing to the position of the setting device.

20. Tuning means for a radio-receiving setincluding a frame, a shaft carried by the frame and operatively connected with a tuning element, a setting device carried on the shaft and having fastening means for securing it to the shaft, a slidable member having one end supported by the shaft and the other end by a frame member, means for operating the slidable member, means on the sliding member for moving the setting device to turn the shaft in either direction of rotation according to the position of the setting device, and means for automatically taking up all play in the parts as a station is tuned in.

21. Tuning means for a radio-receiving set including a frame, a shaft carried by the frame and operativelyconnected with a tuning element, 8. setting device carried on the shaft and having fastening means for securing it to the shaft, a slidable member having one end supported b the shaft and the other end by a frame member, means for operating the slidable member, means on the sliding member for moving the setting device to turn the shaft in either direction of rotation according to the po-- sition of the setting device and means cooperative between, the shaft, the setting device and the slidable member for removing all lost motion and play at the setting device when tuning in a'st'ation.

22. Tuning meansfor a radio-receiving set including a frame, a shaft carried by the frame and operatively connected with a tuning element, a setting device carried on the shaft and having fastening means for securing it to the shaft, a slidable member having one end supported by the shaft and the other end by a frame member, means for operating the slidable member, means on the sliding member for moving the setting device to turn the shaft in either direction of rotation according to the position of the setting device, and means carried by the frame at the front thereof: cooperative with means at the front end 01' the slidable member for eliminating all wobble of the slidable member when it is moved to final tuning position.

23. Tuning means for a radio-receiving set including a frame, a shaft carried by the frame and operatively connected with a tuning element, a setting device carried on the shaft and having fastening means for securing it to the shaft, a slidable member having one end sup- 

